The invention is related generally to fluid delivery devices, and more particularly, to a status indicator for indicating the status of the flow of medical fluid through an administration device.
In the past, prolonged infusion of fluids has often been accomplished using gravity flow methods, which typically involve the use of intravenous administration sets and a bottle or bag of medical fluid suspended above the patient. Such methods are cumbersome, imprecise, and require bed confinement of the patient. Periodic monitoring of the apparatus by the nurse or doctor is required to detect malfunctions of the infusion apparatus.
The apparatus of the present invention can be used with minimal professional assistance in an alternate health care environment, such as the home. By way of example, devices of the invention can be comfortably and conveniently removably affixed to the patient's body and can be used for the continuous infusion of antibiotics, hormones, steroids, blood clotting agents, analgesics, and other medicinal agents. Similarly, the devices can be used for IV chemotherapy and can accurately deliver fluids to the patient in precisely the correct quantities and rates over time.
The present invention is directed, generally, to an ambulatory drug infusion pump for administering antibiotics, antiviral, and other IV medications for critically ill patients and for home care or out-patient applications.
In many situations, a patient may require multiple daily therapies, intermittent infusion, or a slow and continuous introduction of medicament liquid into the patient's system. Moreover, certain therapies require medicament liquid or pharmaceutical solutions to be infused over a particular period of time which may range anywhere from about 30 minutes to about several hours, for a therapeutic dose. It is therefore very important that these medicament liquid or pharmaceutical solution doses be administered completely and with a highly accurate introduction rate (flow rate). Currently, a variety of devices exist that are able to deliver medicament liquids and pharmaceutical solutions intravenously to a patient. In the past few years, certain of these devices have offered some degree or portability, but the most widely utilized of these devices typically require a patient to be confined to a bed, thus limiting the options available for patients who are able to be ambulatory.
So called ambulatory infusion pumps are gaining currency in medical technology, given the trend towards shorter hospital stays and increasing reliance on out-patient and home care treatment. Such ambulatory devices typically function on an infusion pump delivery principle which pumps a medicament liquid or other IV solution into the patient. The pressure developed by the infusion pump is designed to overcome the resistance of the patient's internal pressure and include regulators or restrictors in the IV tubing set to attempt to control the rate of flow of the IV solution into the patient. For example, it is common to pressurize a container filled with a medicament liquid or IV solution by transmitting a hydrostatic or gas pressure developed in an external or internal gas-filled bladder to the IV solution container. By maintaining a constant pressure in the bladder, it was hoped that the bladder would exert (transmit) a constant pressure to the IV solution container, thereby developing a constant flow rate of medicament liquid at the point of infusion.
In the more common elastomeric-type infusion pump devices, the elastomeric pumps use the pressure of an expanding elastomeric element to push an IV solution through a rate controlling orifice or a constrictive clamp. However, the flow rate of these systems are prone to several external factors which are beyond the control of the device and are not outwardly obvious to an uninitiated patient administering the infusion.
The reality with prior art systems is that ambulatory patients are not readily able to determine the status of fluid flow in their infusion system. Thus, patients tend to verify the status of their infusions by disconnecting the pump from the catheter (i.e. break the line) to see if drops form. This practice of breaking the line exposes the infusion line to outside contaminants, creating an infection risk and potentially putting the patient in contact with hazardous chemicals.
Hence, those skilled in the art have recognized a need for a flow indicator device that is easily monitored by a home user to determine if fluid is flowing in the administration line. Further, those skilled in the art have recognized the need for an indicator device that can be used to provide a bolus of medication to a patient. The present invention fulfills these needs and others.